fuse: fix READDIRPLUS skipping an entry

Marios Titas running a Haskell program noticed a problem with fuse's
readdirplus: when it is interrupted by a signal, it skips one directory
entry.

The reason is that fuse erronously updates ctx->pos after a failed
dir_emit().

The issue originates from the patch adding readdirplus support.

Reported-by: Jakob Unterwurzacher <jakobunt@gmail.com>
Tested-by: Marios Titas <redneb@gmx.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 0b05b18381ee ("fuse: implement NFS-like readdirplus support")
Cc: <stable@vger.kernel.org> # v3.9

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 622081b97426d5b439bb1db5ee57dc4c3eead253..24967382a7b15271ae0646c3cb5522b3e58c37d0 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1308,7 +1308,8 @@ static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
                        */
                        over = !dir_emit(ctx, dirent->name, dirent->namelen,
                                       dirent->ino, dirent->type);
-                       ctx->pos = dirent->off;
+                       if (!over)
+                               ctx->pos = dirent->off;
                }
 
                buf += reclen;